Abstract
The sulphhydryl environment in various mixed-metal hybrid hemoglobins, viz. α2(Cu)-β2(FeCO), α2(FeCO)-β2(Cu), α2(Cu)-β2(Ni), α2(Ni)-β2(Cu), was studied by reacting them with the sulphhydryl reagent, 4,4′-dithiodipyridine (4-PDS). The reactivity was compared with that of HbCO, NiHb and CuHb. It is found that there exists a correlation between conformational change and metal ion environment, not only at the extreme R and T states but also the intermediate conformations. EPR examinations of these hybrids show that both in R state-[Cu(II)-Fe(II)] and T state-[Cu(II)-Ni(II)] hybrids at neutral pH and in the absence of IHP, CuPPIX, irrespective of the subunit in which it is present, has a mixed-metal ion environment: Species 1, a five-coordinated Cu2+ complex with strong proximal histidine bond and species 2, a four-coordinated complex without any covalent linkage with Nε F8-histidine.
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Abbreviations
- DTT:
-
dithiothrietol
- EPR:
-
electron paramagnetic resonance
- Hb:
-
hemoglobin
- 4-PDS:
-
4,4′-dithiodipyridine
References
Ackers G K and Smith F T 1987 Annu. Rev. Biophys. Chem. 16 583
Ogawa S and Shulman R G 1972 J. Mol. Biol. 70 315
Ikeda-Saito M, Yamamoto H and Yonetani T 1977 J. Biol. Chem. 252 8639
Miura S and Ho C 1982 Biochemistry 21 6280
Miura S and Ho C 1984 Biochemistry 23 2492
Perutz M F 1972 Nature (London) 237 495
Perutz M F, Fersht A R, Simon S R and Roberts G C K 1974 Biochemistry 13 2174
Perutz M F, Kilmartin J V, Nagai K, Szabo A and Simon S R 1976 Biochemistry 15 378
Inubushi T and Yonetani T 1983 Biochemistry 22 1894
Scott T W, Friedman J M, Ikeda-Saito M and Yonetani T 1983 FEBS Lett. 158 68
Shibayama N and Morimoto H 1986 J. Mol. Biol. 192 331
Shibayama N, Inubushi T, Morimoto H and Yonetani T 1987 Biochemistry 26 2194
Ishimori K and Morishima I 1988 Biochemistry 27 4060
Nagai K and Kitagawa T 1980 Proc. Natl. Acad. Sci. (USA) 77 2033
Maxwell J C and Caughey W S 1976 Biochemistry 15 388
Manoharan P T, Alston K and Rifkind J M 1985 in Biological & inorganic copper chemistry (eds) K D Karlin and J Zubieta (New York: Adeinine Press)
Manoharan P T, Alston K and Rifkind J M 1986 J. Am. Chem. Soc. 108 7095
Shelnutt J A, Alston K, Ho J-Y, Yu N-T, Yamamoto T and Rifkind J M 1986 Biochemistry 25 620
Shibayama N, Ikeda-Saito M, Hori H, Itaroku K, Morimoto H and Saigo S 1995 FEBS Lett. 372 126
Shibayama N, Morimoto H and Miyazaki G 1986 J. Mol. Biol. 192 323
Kilmartin J V, Fogg J, Luzzana M and Rossi-Barnerdi L 1973 J. Biol. Chem. 248 7039
Geraci G, Parkhurst L J and Gibson Q H 1969 J. Biol. Chem. 244 4664
Rossi-Fanelli A, Antonini E and Caputo A 1958 Biochim. Biophys. Acta 30 608
Ampulski R S, Ayers V E and Morell S A 1967 Anal. Biochem 32 163
McLees B D and Caughey W S 1969 Biochemistry 7 642
Makino N and Sugita Y 1982 J. Biol. Chem. 257 163
Fujii M, Hori H, Miyazaki G, Morimoto H and Yonetani T 1993 J. Biol. Chem. 268 15386
Alston K and Storm C B 1979 Biochemistry 79 4292
Manoharan P T and Rogers M T 1969 in ESR of metal complexes (ed.) T F Yen (New York: Plenum Press) p. 143
Venkatesh Rao V, Balakrishnan G and Manoharan P T 2002 Biopolymers 67 156
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Dedicated to the memory of the late Professor Bhaskar G Maiya
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Ramasamy, S., Venkateshrao, S., Rifkind, J.M. et al. Metal ion coordination in ‘R’ and ‘T’ state hybrid hemoglobins as revealed by optical, EPR and sulphhydryl reactivity studies. J Chem Sci 117, 85–97 (2005). https://doi.org/10.1007/BF03356101
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DOI: https://doi.org/10.1007/BF03356101